MULCHING IN BEARING APPLE ORCHARDS 5 



during the war and immediately after, they were somewhat neglected. The 

 interplanted trees and bushes had been removed before 1921. The remaining 

 trees were in good vigor and were beginning to bear commercial crops. 



These two adjoining plots lie on an easterly slope. Below, the land slopes 

 gently easterly to swampy land that has since been tile drained. To the west, 

 somewhat higher sloping land extends to the top of the hill about 300 feet 

 away. The soil is a stony loam underlaid with a rather compact subsoil. It 

 is probable that there is considerable seepage from the higher land through the 

 orchard. 



In the spring of 1922 the lower half of the Mcintosh block and the upper half 

 of the Wealthy block were mulched heavily with low-grade hay. This treat- 

 ment has been continued with somewhat irregular applications of mulching 

 material, gradually extending the mulched area as the trees grew, until now 

 nearly all the surface is covered with material sufficient to prevent the growth 

 of grass or weeds. No record has been kept of the weight of the applied mulch 

 but it has probably been somewhere near a pound per square foot per year. 

 This is probably more than would be advisable in practice. The lower layers are 

 decayed and filled with fine fibrous roots. A few of the Wealthy trees were 

 injured by mice but no more than in other orchards in sod. A space three to 

 four feet in diameter around the trunks was excavated and filled with gravel 

 and there has been no more mouse injury since. Poisoned grain has been 

 placed in the orchard each fall in recent years. 



The other halves of the plots have been under a cultivation - cover crop 

 system. 



No fertilizer has been applied to the mulched plots, and none to the cultivated 

 plots until 1931 when the trees on these plots appeared to be losing vigor. Be- 

 ginning in 1931 an annual application of 100 pounds of nitrate of soda has been 

 made to each cultivated plot. Growth of the cover crop has varied in different 

 years but has generally been small. It has been somewhat heavier following 

 the use of nitrogen, but cannot have been enough to maintain the organic matter 

 of the soil. 



Conditions in the Soil 



During the summers of 1925 and 1926 soil samples from each of the four plots 

 were taken weekly during the growing season and at less frequent intervals up 

 to January 15. The soil temperature was noted each time and a mechanical 

 analysis of the soil was made. The results of this work have been reported by 

 Beaumont and others (1, 2) . Very fine sand predominates in the soil (33.8 

 percent). There is considerable silt (19.7 percent) and some clay (9.7 percent). 

 Soil temperatures did not differ much according to soil treatment, but in mid- 

 summer the soil sometimes was one or two degrees cooler under the mulch. 

 Soil moisture differed less than might be expected. In the Wealthy block the 

 average was practically the same both years under the two treatments, while 

 in the Mcintosh block soil moisture was considerably higher under the mulch. 

 This means that the location of the plots had more effect on soil moisture than 

 the treatment. The mulched Mcintosh and cultivated Wealthy plots were 

 lower and were naturally more moist than the other two plots. The mulching 

 overcame this difference in the Wealthy plots, while the natural difference in 



